NAME¶

system_cronjob_selinux - Security Enhanced Linux Policy for the system_cronjob processes

DESCRIPTION¶

Security-Enhanced Linux secures the system_cronjob processes via flexible mandatory access control.

The system_cronjob processes execute with the system_cronjob_t SELinux type. You can check if you have these processes running by executing the ps command with the -Z qualifier.

For example:

ps -eZ | grep system_cronjob_t

ENTRYPOINTS¶

The system_cronjob_t SELinux type can be entered via the shell_exec_t, bin_t, system_cron_spool_t, usr_t, anacron_exec_t, fusefs_t, nfs_t, cifs_t file types.

The default entrypoint paths for the system_cronjob_t domain are the following:

All executeables with the default executable label, usually stored in /usr/bin and /usr/sbin. /bin/d?ash, /bin/zsh.*, /bin/ksh.*, /usr/bin/d?ash, /usr/bin/ksh.*, /usr/bin/zsh.*, /bin/esh, /bin/mksh, /bin/sash, /bin/tcsh, /bin/yash, /bin/bash, /bin/fish, /bin/bash2, /usr/bin/esh, /usr/bin/sash, /usr/bin/tcsh, /usr/bin/yash, /usr/bin/mksh, /usr/bin/fish, /usr/bin/bash, /sbin/nologin, /usr/sbin/sesh, /usr/bin/bash2, /usr/sbin/smrsh, /usr/bin/scponly, /usr/sbin/nologin, /usr/libexec/sesh, /usr/sbin/scponlyc, /usr/bin/git-shell, /usr/libexec/sudo/sesh, /usr/bin/cockpit-bridge, /usr/libexec/cockpit-agent, /usr/libexec/git-core/git-shell, /etc/cron.d(/.*)?, /var/spool/anacron(/.*)?, /etc/crontab, /var/spool/fcron/systab, /var/spool/fcron/new.systab, /var/spool/fcron/systab.orig, /usr/.*, /opt/.*, /emul/.*, /export(/.*)?, /ostree(/.*)?, /usr/doc(/.*)?/lib(/.*)?, /usr/inclu.e(/.*)?, /usr/share/doc(/.*)?/README.*, /usr, /opt, /emul, /usr/sbin/anacron, /var/run/user/[^/]*/gvfs

PROCESS TYPES¶

SELinux defines process types (domains) for each process running on the system

You can see the context of a process using the -Z option to ps

Policy governs the access confined processes have to files. SELinux system_cronjob policy is very flexible allowing users to setup their system_cronjob processes in as secure a method as possible.

The following process types are defined for system_cronjob:

system_cronjob_t

Note: semanage permissive -a system_cronjob_t can be used to make the process type system_cronjob_t permissive. SELinux does not deny access to permissive process types, but the AVC (SELinux denials) messages are still generated.

BOOLEANS¶

SELinux policy is customizable based on least access required. system_cronjob policy is extremely flexible and has several booleans that allow you to manipulate the policy and run system_cronjob with the tightest access possible.

If you want to allow users to resolve user passwd entries directly from ldap rather then using a sssd server, you must turn on the authlogin_nsswitch_use_ldap boolean. Disabled by default.

setsebool -P authlogin_nsswitch_use_ldap 1

If you want to allow system cron jobs to relabel filesystem for restoring file contexts, you must turn on the cron_can_relabel boolean. Disabled by default.

setsebool -P cron_can_relabel 1

If you want to allow system cronjob to be executed on on NFS, CIFS or FUSE filesystem, you must turn on the cron_system_cronjob_use_shares boolean. Disabled by default.

setsebool -P cron_system_cronjob_use_shares 1

If you want to allow all daemons to write corefiles to /, you must turn on the daemons_dump_core boolean. Disabled by default.

setsebool -P daemons_dump_core 1

If you want to enable cluster mode for daemons, you must turn on the daemons_enable_cluster_mode boolean. Enabled by default.

setsebool -P daemons_enable_cluster_mode 1

If you want to allow all daemons to use tcp wrappers, you must turn on the daemons_use_tcp_wrapper boolean. Disabled by default.

setsebool -P daemons_use_tcp_wrapper 1

If you want to allow all daemons the ability to read/write terminals, you must turn on the daemons_use_tty boolean. Disabled by default.

setsebool -P daemons_use_tty 1

If you want to deny user domains applications to map a memory region as both executable and writable, this is dangerous and the executable should be reported in bugzilla, you must turn on the deny_execmem boolean. Enabled by default.

setsebool -P deny_execmem 1

If you want to deny any process from ptracing or debugging any other processes, you must turn on the deny_ptrace boolean. Enabled by default.

setsebool -P deny_ptrace 1

If you want to allow any process to mmap any file on system with attribute file_type, you must turn on the domain_can_mmap_files boolean. Enabled by default.

setsebool -P domain_can_mmap_files 1

If you want to allow all domains write to kmsg_device, while kernel is executed with systemd.log_target=kmsg parameter, you must turn on the domain_can_write_kmsg boolean. Disabled by default.

setsebool -P domain_can_write_kmsg 1

If you want to allow all domains to use other domains file descriptors, you must turn on the domain_fd_use boolean. Enabled by default.

setsebool -P domain_fd_use 1

If you want to allow all domains to have the kernel load modules, you must turn on the domain_kernel_load_modules boolean. Disabled by default.

setsebool -P domain_kernel_load_modules 1

If you want to allow all domains to execute in fips_mode, you must turn on the fips_mode boolean. Enabled by default.

setsebool -P fips_mode 1

If you want to enable reading of urandom for all domains, you must turn on the global_ssp boolean. Disabled by default.

setsebool -P global_ssp 1

If you want to allow confined applications to run with kerberos, you must turn on the kerberos_enabled boolean. Enabled by default.

setsebool -P kerberos_enabled 1

If you want to control the ability to mmap a low area of the address space, as configured by /proc/sys/vm/mmap_min_addr, you must turn on the mmap_low_allowed boolean. Disabled by default.

setsebool -P mmap_low_allowed 1

If you want to allow system to run with NIS, you must turn on the nis_enabled boolean. Disabled by default.

setsebool -P nis_enabled 1

If you want to allow confined applications to use nscd shared memory, you must turn on the nscd_use_shm boolean. Disabled by default.

setsebool -P nscd_use_shm 1

If you want to disable kernel module loading, you must turn on the secure_mode_insmod boolean. Enabled by default.

setsebool -P secure_mode_insmod 1

If you want to boolean to determine whether the system permits loading policy, setting enforcing mode, and changing boolean values. Set this to true and you have to reboot to set it back, you must turn on the secure_mode_policyload boolean. Enabled by default.

setsebool -P secure_mode_policyload 1

If you want to allow unconfined executables to make their heap memory executable. Doing this is a really bad idea. Probably indicates a badly coded executable, but could indicate an attack. This executable should be reported in bugzilla, you must turn on the selinuxuser_execheap boolean. Disabled by default.

setsebool -P selinuxuser_execheap 1

If you want to allow all unconfined executables to use libraries requiring text relocation that are not labeled textrel_shlib_t, you must turn on the selinuxuser_execmod boolean. Enabled by default.

setsebool -P selinuxuser_execmod 1

If you want to allow unconfined executables to make their stack executable. This should never, ever be necessary. Probably indicates a badly coded executable, but could indicate an attack. This executable should be reported in bugzilla, you must turn on the selinuxuser_execstack boolean. Enabled by default.

setsebool -P selinuxuser_execstack 1

If you want to support X userspace object manager, you must turn on the xserver_object_manager boolean. Enabled by default.

setsebool -P xserver_object_manager 1

MANAGED FILES¶

The SELinux process type system_cronjob_t can manage files labeled with the following file types. The paths listed are the default paths for these file types. Note the processes UID still need to have DAC permissions.

file_type

all files on the system

COMMANDS¶

semanage fcontext can also be used to manipulate default file context mappings.

semanage permissive can also be used to manipulate whether or not a process type is permissive.

semanage module can also be used to enable/disable/install/remove policy modules.

semanage boolean can also be used to manipulate the booleans

system-config-selinux is a GUI tool available to customize SELinux policy settings.

AUTHOR¶

This manual page was auto-generated using sepolicy manpage .

SEE ALSO¶

selinux(8), system_cronjob(8), semanage(8), restorecon(8), chcon(1), sepolicy(8) , setsebool(8)